1. Field of Invention
This invention relates to a machine which is capable of cutting any one of numerous sizes of disposable containers such as plastic bottles and/or metal cans into small pieces and to such a machine which is configured to insure that the small pieces are directed below the cutting area of the machine for collection and disposition. A similar configuration is employed on an improved machine which is capable of cutting paper material into strips of paper to insure that the strips do not collect in a region behind the cutting wheels.
2. Description of the Prior Art
U.S. Pat. No. 4,923,126, which is incorporated by reference in its entirety herein, discloses a machine which is capable of cutting into small pieces the thin wall material of a plurality of disposable containers such as plastic bottles and metal cans. The cutting section of the machine includes a pair of parallel shafts mounted for rotation in opposite directions about the center axes thereof. Each of the shafts rigidly supports a plurality of overlapping cutting wheels for rotation therewith. Each cutting wheel has a plurality of identical cutting teeth with each tooth having an apex at the maximum diameter and a root at a root diameter of the cutting wheel. Each cutting tooth has a leading surface and a trailing surface which meet at the apex to form a straight edge at the maximum diameter which is parallel to the center axis of the shaft. The leading surface and the trailing surface respectively lie in planes which are parallel with the center axis of the shaft and extend toward the same side thereof to cause the straight edge of the apex to circumfrentially lead a remainder of the leading surface during rotation of the cutting wheel.
The basic cutting wheel configuration has been found to effectively and reliably produce the small pieces of the containers as disclosed therein. Generally, the embodiment in U.S. Pat. No. 4,923,126 is configured to cause most of the small pieces to be ejected downwardly from the cutting area between the cutting wheels. A dispersing section below the cutting area is intended to disperse the small pieces throughout a collecting section therebelow. The small pieces are received within a container in the collecting section and eventually removed for further disposition. However, it has been found that suctioning or vacuuming means disposed in the lower area of the machine is preferred in order to transport the small pieces to a larger container remote from the machine itself. In either case, it is clearly desirable that all of the small pieces produced in the cutting section be discharged from the cutting area and to be prevented from collecting around the cutting wheels or the cutting shafts.
As further discussed in U.S. Pat. No. 4,923,126, such machines are typically utilized for the cutting of disposable containers employed in the soft drink industry. As a result, there have been continuing problems with the cutting of such disposable containers which have not typically existed in the operation of other types of cutting machines found in the prior art. The soft drink liquid remaining in the disposable containers has been found, in a short time of operation, to completely engulf the interior of the container cutting machine. The liquid is extremely corrosive and the sugary substance can cause even greater problems when heated. The friction created by the rotating cutting wheels can produce a build up of solid, corrosive by-products that can seriously reduce the effectiveness and even the life of the machine. Additionally, because the soft drink liquid is deposited on many of the small pieces produced by the cutting machine, the small pieces also become sticky and tend to collect in the area of the cutting wheels to present significant problems with continued and effective operation of the machine. As a result, it is desirable for the cutting section to be configured to prevent the collection of such corrosive and destructive pieces therein.
In order to determine an effective way for preventing the collection of such small pieces in the cutting section of the machine, it is appropriate to analyze the types of combing means which have been employed in other cutting or shredding machines which were not specifically adapted for the cutting and shredding of containers found in the soft drink industry.
One group of such devices disclosed in prior art patents includes some form of combing means located at the backside of the spacer element between the cutting wheels. These spacer combers prevent the collection of pieces or strips of material between the cutting wheels at the backside thereof. Various cutting machines including such combing configurations are disclosed in U.S. Pat. No. 3,931,935; British Patent Nos. 1,558,423 and 2,059,904; German Patentschrift No. 249,359; German Auslegeshrift No. 1,291,606; and German Offenlegungsschrift Nos. 2,526,650; 2,723,281; 3,231,341; and 3,313,231.
All of the devices disclosed in these patents are characterized by the inclusion of some type of separate or integrally formed annular spacer ring between adjacent cutting wheels or discs on one shaft. The annular spacer ring tends to serve as a rotating comber for the aligned cutting wheel or disc on the other shaft. As a result, the pieces or strips of material are maintained in close proximity with the cutting wheel or disc by which they are formed. The spacer ring rotates in the direction of movement through the cutting area to facilitate the formation of the pieces or strips and their passage through the cutting area of the machine.
The devices disclosed therein are also characterized by the inclusion of a fixed "combing" means or "scraping" device which tends to prevent the collection of any material around the rotating spacer ring. The location of the fixed combing means at the lower or rear region of each spacer ring would prevent the collection of the strip or piece material at the backside of the spacer ring remote from the cutting area. However, as will be seen, the general shape and form of such combing means may not be satisfactory for the "combing" or "scraping" of the small pieces formed from soft drink containers because of the soft drink liquid tending to form and collect thereon.
Another group of cutting or shredding machines also includes additional means for preventing the collection of small pieces of material at the remote side of the cutting wheels themselves rather than simply at the remote or backside of the spacer ring. Such cutting or shredding machines are disclosed in U.S. Pat. Nos. 4,068,805 and 4,702,422; French Patent No. 45,173; and Japanese Patent Nos. 55-136597 and 63-232860. All of these machines apparently incorporate a solid comber block or backing member which occupies the space within the housing at the backside of both the rotating cutting wheels and the spacer rings therebetween. U.S. Pat. No. 4,693,428 discloses a particle-type shredding mechanism with a stacked array of spacer and cutting wheel combers. Such configurations will again tend to prevent most of the pieces or strips from being carried about the interior of the machine with the rotating cutting discs and spacers. To a greater or lesser degree, each of these prior art comber configurations will tend to prevent the collection of such pieces or strips in the region remote from the cutting area. However, as will be seen later, the particular configurations of the prior art combing devices aligned with the cutting discs and with the spacer rings do not entirely prevent the undesired collection of the type of small pieces produced by the cutting of plastic bottles and/or metal cans found in the soft drink industry.
While the preferred configuration was particularly adapted for preventing the undesired collection of small pieces produced by the cutting of plastic bottles and/or metal cans found in the soft drink industry, it has also been determined that a similar configuration of cutting wheel combers could be employed in a conventional paper shredding machine to provide an improved machine for cutting such paper material. Although the paper shredding machine includes a different comber-spacer configuration between the cutting wheels, the preferred cutting wheel comber which partially encircles the remote side of the cutting wheels employed in such paper shredders would also advantageously prevent the collection of paper at the remote side of the cutting wheels.
All of the U.S. and foreign patents discussed hereinabove are incorporated by reference as if included in their entirety herein.